Traditional push-to-talk (PTT) services have been defined with strict floor control policies in mind where right-to-speak is enforced through a floor request procedure or a floor grant procedure during a PTT session that includes tones or announcements to indicate to a user when he shall start and stop speaking. One advantage of these procedures is that the PTT system always ensures that only one person speaks at a time. However, one disadvantage is that volley times (i.e. the time it takes from that one person stops speaking until he gets a audio response back) are often considered too long.
Push-to-talk Over Cellular (PoC) is standardized by Open Mobile Alliance (OMA). This standard is discussed in greater detail in the following technical specifications:
“Push to talk over Cellular Requirements”, Candidate Version 1.0—29 Mar. 2005, OPEN MOBILE ALLIANCE™, OMA-RD-PoC-V1_0-20050329-C;
“Push to talk over Cellular Architecture”, Candidate Version 1.0—27 Jan. 2006, OPEN MOBILE ALLIANCE™, OMA-AD_PoC-V1_0-20060127-C;
“PoC Control Plane”, Candidate Version 1.0—27 Jan. 2006, OPEN MOBILE ALLIANCE™, OMA-TS-PoC-ControlPlane-V1_0-20060127-C; and
“PoC User Plane”, Candidate Version 1.0—27 Jan. 2006, OPEN MOBILE ALLIANCE™, OMA-TS_PoC-UserPlane-V1_0-20060127-C, which are hereby incorporated by reference in their entirety.
The OMA PoC Version 1 standard utilizes a Talk Burst Control Protocol (TBCP) for allocating the floor to a PoC session participant. TBCP is detailed in the OMA PoC User Plane specification. A high-level overview also exists in the OMA PoC Architecture document. The PoC server TBCP state machine manages the allocation of floor to PoC session participants. In the basic usage scenario, i.e. with no queuing of floor requests, a participant can only request the floor once the floor idle indication is received. The floor idle indication is given in the form of a tone and/or a visual display. If the participant attempts to take the floor prior to receiving a floor idle indication, then this floor request will be rejected with an error message, e.g. “other user speaking” and/or associated floor deny tone. When requesting the floor after having received a floor idle indication, the participant will need to wait for a floor granted indication before being able to speak. This time delay is added into the standard in order to ensure that only one participant can be given the floor at any given time. However, from a usability perspective, this time delay is often seen as a nuisance as the participant must depress the PTT button while waiting and listening carefully for a right-to-speak tone/visual display from the phone before starting to speak.
There is also a Version 2 of the OMA PoC Specification. The current draft documents for this release are:
“Push to talk over Cellular Requirements”, Draft Version 2.0—14 Feb. 2006, OPEN MOBILE ALLIANCE™, OMA-AD_PoC-V2_0-20060214-D; and
“Push to talk over Cellular Architecture”, Draft Version 2.0—15 Feb. 2006, OPEN MOBILE ALLIANCE™, OMA-RD-PoC-V2_0-20060215-D, which are hereby incorporated by reference in their entirety.
Some enhancements are proposed to the Talk Burst Control Protocol (TBCP) in the OMA PoC Version 2 Requirements document of which “pre-granted media burst control” is the capability that comes closest to the current invention. Pre-granted media burst control would allow the PoC server to send a floor grant to a participant without a prior floor request. This would avoid one round-trip on the wireless network, i.e. avoiding the need to send a floor idle message from the PoC server and a floor request from the pre-granted participant. Pre-granting the floor in this manner is seen as most suitable for 1-to-1 sessions (e.g. sessions with only 2 participants), where it is likely that the participants will take turns to speak. As such a PoC server can be programmed with a simple pre-granting rule. However, no algorithms for providing smart pre-granting rules for the general case of PoC group sessions (e.g. 3 or more participants in a session) have been proposed in OMA as it typically is too difficult to predict user behavior in such scenarios. Furthermore, pre-granting the floor to a participant that is not in a position to speak can become a privacy issue if an outgoing media path from the pre-granted participant is opened automatically by the PoC client after a pre-granted floor message is received from the PoC server.
As can be understood from the pre-granted PoC group session scenario it is difficult to predict expected user behavior and as such to define the correct programming algorithm for the PoC server to apply. Some limitations of such schemes lies in the attempt to have the technology control the user. The present invention suggests a different approach (i.e. user controlled speculative media transfer) to achieve the same benefit (i.e. avoid one-roundtrip of floor control messages and as such reduce the volley time). The present invention provides for any participant to speculatively start speaking and sending media during a floor idle state rather than requiring a PoC server try to predict which user that is likely to speak next. That is, the user rather than the PoC server is in control.
Therefore, attempts to reduce the volley time by way of opportunistically sending media are provided if a floor idle indication has been received from the PTT system and as such avoiding at least one roundtrip of floor request-floor grant signaling over the wireless network. As such, systems and methods for implementing lazy-lock control procedures in real-time communication services are presented herein.